B-lifetime measurements at CDF

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The average b-hadron lifetime has been measured using a high statistics sample of B {yields} J/{psi}X decays recorded with the Collider Detector at Fermilab. The decay vertices of J/{psi} {yields} {mu}{sup +}{mu}{sup {minus}} candidates have been reconstructed using information from a silicon vertex-detector. The measured B lifetime, which is the average over all b-hadrons produced in p{bar p} collisions at {radical}s = 1.8 TeV, weighted by their branching ratios into J/{psi} is: {tau}B = 1.46 {plus_minus} 0.06(stat.) {plus_minus} 0.06(sys.)ps (preliminary); In addition we used the fully reconstructed final states B{sup {plus_minus}} {yields} J/{psi}K{sup {plus_minus}} and B{sup 0} {yields} J/{psi}K{sup 0}* to measure the exclusive lifetime of charged and neutral B-mesons. We measure: {tau}{sub B}{sup {plus_minus}} = 1.59 {plus_minus} 0.27(stat.) {plus_minus} 0.17(sys.) ps (preliminary); {tau}{sub B}{sup 0} = 1. 34 {plus_minus} 0.31 (stat.) {plus_minus} 0.17 (sys.) ps (preliminary); From this we obtain the following result for the lifetime ratio: {tau}{sub B}{sup {plus_minus}}/{tau} {sub B}{sup 0} = 1.19 {plus_minus} 0.35(stat.) {plus_minus} 0.12(sys.) (preliminary); This represents the first measurements of the b-lifetime at a hadron collider.